"Studies reporting estimates of high-risk drug use can help to identify the extent of the more entrenched drug use problems, while data on first-time entrants to specialised drug treatment centres, when considered alongside other indicators, can inform an understanding of the nature of and trends in high-risk drug use.

"Opioids, particularly heroin, remain associated with the greatest health and social harms caused by illicit drugs in the United Kingdom. While there has been a decline in the prevalence of injecting among opioid users, around one third of people who seek treatment for heroin use in England report use by injection. There are concerns about changes in the patterns of drug injection in the United Kingdom, in particular the increased injection of crack cocaine and amphetamine-type stimulants, and the emergence in recent years of the injection of NPS. Data from the 2017 Unlinked Anonymous Monitoring survey of people who inject drugs indicate that the injection of crack has increased in recent years in England and Wales, with 51 % of those who had injected during the preceding 4 weeks reporting the injection of crack cocaine.

"Data on the characteristics of those entering treatment in the United Kingdom indicate that heroin is the most commonly reported primary substance among those seeking treatment for drug use problems; however, there has been a long-term reduction in first-time clients seeking treatment for heroin use. Among first-time treatment clients, cannabis is the most commonly reported substance, followed by cocaine. An increase in the number and proportion of first-time treatment entrants for cocaine (both powder and crack) has been reported since 2014. Presentations to community treatment services for primary use of NPS have decreased markedly in England, and problematic NPS use is now found primarily among the adult prison population and street homeless people. Studies among vulnerable populations, such as homeless people, suggest that the use of synthetic cannabinoid receptor agonists is high among this group."

Source

European Monitoring Centre for Drugs and Drug Addiction (2019), United Kingdom Country Drug Report 2019, Publications Office of the European Union, Luxembourg.